We refer to the network to be evaluated as the target system.

At any time t, the prototyper maintains the following:

• control state (state of the control algorithms)
• target system arrival rates (part of target system specification)
• MCMR arrival rates (inferred from target system arrival rates and control state)
• MCMR performance measures
• target system performance measures (inferred from the MCMR measures and control state).
• time of the next control algorithm update.

The evolution of the MCMR performance measures is obtained using Z-iteration until the time of the next control update, at which point the control state changes (as a function of the target system performance measures). This in turn sets new MCMR arrival and service rates for the next Z-iteration cycle.
 

The Z-prototyper package implements the above evaluation method. It has the following:

A Z-iteration library of functions for evaluating MCMR queues.

A simulation library of functions to for simulating MCMR queues. This simulator is provided for validation purposes only; in general, it will take far more computation time than the Z-iteration evaluator.

A common API for the simulation and Z-iteration libraries. Thus an application can readily switch between the two evaluation methods.

A collection of target system models. Currently they are of connection-oriented networks with dynamic routing, link scheduling, admission control (and the resulting resource reservation). Each target workload class represents a stream of connection requests with the following attributes: source and destination node for the connection requests, rate at which the requests are generated, traffic descriptors of the requests (eg, peak and avg rates, burstiness), desired QoS of the requests (eg, end-to-end delay/jitter of either statistical or deterministic flavor, maximum loss probability), and duration of established connections.

An on-line network evaluator for a simplified version of the above connection-oriented networks; specifically, bandwidth requirement is the only QoS and average request rate is the only traffic descriptor. The on-line evaluator has a java applet for constructing target systems, a server (not an applet) for doing Z-iteration evaluation, and a collection of predefined target systems. It is best run using Sun's appletviewer.

The on-line network evaluator (client only) is also available as a separate package.

You are welcome to try the on-line network evaluator through a web browser (Netscape 4.0 or higher). But there are constraints: You will have to enable your browser to access slimjim.cs.umd.edu, because that is where the server is located. You will also not have full capabilities, such as saving and loading the predefined target systems.